2-Fluorobenzoyl isothiocyanate → tert-butyl 2-(3-(2-fluorobenzoyl)thioureido)-5,5-dimethyl-5,7-dihydro-4H-thieno[2,3-c]pyran-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 2-amino-5,5-dimethyl-5,7-dihydro-4H-thieno[2,3-c]pyran-3-carboxylate (50 mg, 0.18 mmol) in THF (3 mL) was added 2-fluorobenzoyl isothiocyanate (35.2 mg, 0.19 mmol) and the mixture heated at 60° C. for 16 h. The solvent was removed in vacuo. The residue was sonicated (1 min) with cold EtOH, filtered and the resulting solid rinsed with cold EtOH to yield tert-butyl 2-(3-(2-fluorobenzoyl)thioureido)-5,5-dimethyl-5,7-dihydro-4H-thieno[2,3-c]pyran-3-carboxylate (41 mg, 0.088 mmol, 50% yield) as a pale yellow solid. 1H NMR (400 MHz, CDCl3) δ 14.70 (s, 1H), 9.69 (s, 1H), 8.25-8.11 (m, 1H), 7.63-7.49 (m, 1H), 7.36-7.26 (m, 1H), 7.23-7.17 (m, 1H), 4.72 (s, 2H), 2.73 (d, J=6.3, 2H), 1.58 (d, J=2.4, 9H), 1.29 (d, J=1.7, 6H). 13C NMR (101 MHz, CDCl3) δ 173.27, 164.59, 161.79, 161.21, 161.18, 159.30, 147.36, 135.67, 135.57, 132.79, 129.15, 125.37, 125.34, 124.64, 119.06, 118.96, 118.06, 116.70, 116.46, 82.42, 70.79, 59.81, 38.24, 28.49, 26.48.

Provenance & Evidence